Study Supports Use of Progesterone to Fight Pre-Term Birth

A new study recently published in the American Journal of Obstetrics & Gynecology provides additional support for treatment with vaginal progesterone to reduce the risk of pre-term birth, neonatal complications and infant death in pregnant women with a short cervix. A shortened cervix is the most powerful predictor of pre-term birth.

A meta-analysis of individual patient data by researchers at the Perinatology Research Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the Wayne State University School of Medicine and the Detroit Medical Center, further validates the use of vaginal progesterone to decrease the risk of pre-term birth and improve perinatal outcomes in women with a single pregnancy found via sonography to have a short cervix. Vaginal progesterone therapy to reduce pre-term birth was developed at the PRB in 2011.

Births occurring before the 37th week of pregnancy are considered pre-term. In preparation for birth, the cervix (lower part of the uterus) thins and shortens during pregnancy. In some women, the cervix shortens prematurely. The natural hormone progesterone, inserted in the vagina either as a gel or tablet, has been associated with a reduction of the risk for pre-term birth associated with a short cervix in multiple studies conducted by National Institutes of Health and WSU investigators.

To confirm progesterone’s effectiveness, the researchers investigated randomised controlled studies that compared women who received vaginal progesterone with those who received a placebo or no treatment for a single birth and a mid-trimester sonographic cervical length of less than 25 mm.

The study examined data from 974 women (498 assigned to vaginal progesterone and 476 assigned to placebo) who participated in one of five trials. The use of progesterone was associated with a significant reduction in the risk of pre-term birth at less than 33 weeks gestation. Progesterone use also significantly decreased the risk of pre-term birth from less than 36 weeks to 28 weeks gestation. Women who used progesterone delivered closer to their due date than did women supplied with placebos.

The use of progesterone also significantly decreased the rate of respiratory distress syndrome, neonatal death, low birthweight and admission to neonatal intensive care units for newborns with no deleterious effects on childhood neurodevelopment.

‘This study addresses a controversy that emerged after the publication of another study in February 2016. Our meta-analysis demonstrates that vaginal progesterone reduces the rate of pre-term birth from less than 28 weeks to less than 26 weeks in women with a sonographic short cervix. Moreover, vaginal progesterone reduces admission to NICU, respiratory distress syndrome and composite neonatal morbidity,’ said Roberto Romero, MD, Chief of the PRB and Professor of Molecular Obstetrics and Genetics for the Wayne State University School of Medicine, lead author of the study.

‘Our results, coupled with those of cross-effectiveness research and implementation research, shows that universal cervical screening of the uterine cervix with the administration of vaginal progesterone is cost-effective and can be implemented in the real world.’